A FOLDABLE TENT

Abstract: A foldable tent has a flexible enclosure (1) secured to a frame (2). When the tent is erect the frame (2) is outwardly tensioned under restraint of the enclosure (1). The frame (2) has a plurality of folding supporting legs (3-6) with joints (8, 9). Some (8) of the joints are provided with locking means (10-12; 13-16) operated by over centre toggle action handles (10; 13) for opening the joint (8) with mechanical advantage. The locking means is adapted to lock the respective joint (8) in a partially open position in the course of erection of the tent. The structure of the tent permits it to be folded into a smaller package than has hitherto been possible.

Description: A FOLDABLE TENT This invention relates to a foldable tent and particularly but not exclusively to a foldable work tent of the kind used for example as a temporary structure for the purpose of protecting electrical equipment exposed to the environment during repair and maintenance work on roads. It is known to provide a foldable work tent comprising a collapsible frame secured to a flexible fabric enclosure foldable with the frame into a compact package that can be stowed in a workmans van. There is an increasing demand for work tents which are capable of being folded into smaller packages taking up less storage space. It is an object of the present invention to provide a foldable tent having a structure which permits the tent to be folded into a smaller package than has hitherto been possible. According to the present invention there is provided a foldable tent comprising a flexible enclosure secured to a frame which is adapted to be outwardly tensioned under the restraint of the enclosure when the tent is erect characterised in that the frame has a plurality of folding supporting legs with joints of which at least some are provided wit-., locking means including an actuating handle for opening the joint with mechanical advantage. Preferably, the locking means is adapted to lock the respective joint in a partially open position in the course of erection of the tent. The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 shows a folding work tent in accordance with the invention in a nearly fully erected position; Fig. 2 shows the work tent in a partially collapsed condition; Figs. 3A to 3D are side views of one embodiment of frame joint in successive stages of opening; Figs. 4A to 4C are similar views of a second embodiment of joint; Figs. 5 and 6 are enlarged perspective views of the joint of Fig. 4 in an intermediate position, and Figs. 7 and 8 show an alternative joint in partially open and fully open positions respectively. Referring now to the drawings, the folding tent shown in Figs. 1 and 2 comprises a flexible fabric enclosure 1 of upright box-shape with full vertical side walls and a top wall. A frame 2 has four legs 3-6 extending outwardly from a common joint 7 positioned centrally of the top wall of the enclosure 1. Each leg 3-6 is constructed in three sections accommodated in respective sleeves of the enclosure 1 so that the legs extend diagonally of the top wall and vertically down a respective edge of the enclosure 1 in the erected condition thereof. The upper sections of the legs 3-6 are foldable upwardly with respect to the joint 7 as seen in Fig. 1. The joint 7 is so designed that downward movement of the legs 3-6 beyond the illustrated position involves overcoming the joint resistance thereby placing the legs under an upwardly acting tension which is restrained by the enclosure 1 thereby serving to keep the tent in a stable erect condition. The three leg sections are of unequal length with the lower section, which is provided with a terminal foot, being of greater length than the intermediate section such that in the folded condition, in which the leg sections lie parallel to each other, the lower leg section extends beyond a joint 8 interconnecting the upper and intermediate sections. The intermediate and lower sections of each leg are interconnected by a joint 9. The joints 8 and 9 act in opposite directions with the joints 8 moving inwardly during opening while the joints 9 move outwardly. As will be further described below, the joints 8 are adapted to be fully opened by means of a toggle action lever movable in the direction of the arrows in Fig. 1 to lock the joints in the open position in which the legs are bowed outwardly to the maximum extent as indicated by the dotted lines in Fig. 1. In this condition both the joints 8 and 9 of all the legs are in the fully open position with the joints 8 locked against closure movement and the joints 9 bent against the joint resistance. Figs. 3A to 3D show one embodiment of the joint 8 in the fully closed position (Fig. 3A), first and second stages of the opening movement (Figs. 3B and 3C) and the fully open and locked position (Fig. 3D). The joint 8 comprises an over-centre toggle action lever including a handle 10 pivotally mounted on one component of the joint and connected to a lever link 11 for engagement in a notch 12 of the other joint component. As the joint 8 opens from the position of Fig. 3A into the position of Fig. 3B the lever link 11 engages with the other joint component and eventually (Fig. 3C) drops into the notch 12 whereupon the handle 10 can be toggled back into its starting position so as to force the joint 8 into its fully open position with the joint components tightly engaged. By virtue of the over-centre toggle action of the handle 10 and lever link 11 arrangement a substantial mechanical advantage is achieved in opening the joint 8. Figs. 4, 5 and 6 illustrate a second embodiment of the joint 8 in which there is a similar over-centre toggle action with attendant mechanical advantage involving in this case a handle 13, lever link 14 and notch 15. With the lever link 14 engaged in the notch 15 (Fig. 4A) in the closed condition of the joint 8 the handle 13 is moved clockwise to open the joint into an intermediate position (Fig. 4B) and then over-centre into the fully open position with the joint components interlocked (Fig. 4C). As best seen in Figs. 5 and 6, the handle 13 is provided with an integral cross bar 16 which has a double taper at its ends to facilitate passage through the lever link 14 which is constructed as a rectangular wire frame pivoted in the handle 13. As the handle 13 is moved from the position of Fig. 4A to that of Fig. 4B, the cross bar 16 engages the lever link 14 and by deflecting the side arms thereof (Fig. 5) snaps through the link 14 into the position shown in Figs. 4B and Fig. 6. In this intermediate locking position the handle 13 is effectively held against return movement and the joint 8 is maintained in its partially open position. When erecting the tent the leg sections are first folded outwardly of the joint 7 with the joints 8 fully unlocked. If the joints 8 are of the kind described with reference to Figs. 4 to 6 these joints are then moved into the intermediate locking position so as to give the tent sufficient stability that it can be placed in the erect position of Fig. 1. The joints 8 are then moved to the fully locked position by operating the handles 13 with the result that the joints 8 are fully opened and the legs extend into the positions shown in dotted line in Fig. 1. Quick release is accomplished by rotating the handles 13 in the reverse direction through the intermediate locking position thereby enabling the tent to be fully collapsed. It will be appreciated that numerous modifications may be made without departing from the scope of the invention. For example, the illustrated tent has an external frame but there is no reason in principle why the frame should not be inside the enclosure. In fact, there may be an advantage in this arrangement in that it would enable the user to support the tent in its erect position by standing inside the structure and holding the central joint 7 aloft above his head using one hand. With the other hand he could then lock out each of the four corner joints in turn. In order to facilitate such operation the lever toggle arrangement is reversed as shown in Figs. 7 and 8 so that it works on the inside of the joint rather than the outside of the joint, i.e. it acts as a brace rather than a tensioner. As previously, there is a handle pivoted to one of the joint components and a lever link pivotally interconnecting the centre of the handle with the other joint component. The arrangement is such that the handle and lever link move into an over-centre position (Fig. 8) as the handle is moved in the direction of the arrow in Fig. 7 to force the lower joint component outwardly as indicated by the arrow in Fig. 7. The fabric enclosure may be equipped with a removable or opening pane' as a doorway in one or more of the sides. On those sides where the enclosure wall is not continuous, a linking element is preferably added between adjacent legs and close to ground level is order to maintain the required tension in the erected structure. These links may be in the form of flexible cords or tapes.

Claims: CLAIMS: 1. A foldable tent comprising a flexible enclosure secured to a frame which is adapted to be outwardly tensioned under the restraint of the enclosure when the tent is erect characterised in that the frame has a plurality of folding supporting legs with joints of which at least some are provided with locking means including an actuating handle for opening the joint with mechanical advantage. 2. A foldable tent according to claim 1, wherein the locking means is adapted to lock the respective joint in a partially open position in the course of erection of the tent. 3. A foldable tent according to claim 1 or 2, the handle being an over centre toggle action lever. 4. A foldable tent according to claims 1 , 2 or 3, the locking means comprising a link connected to said handle, the link being engagable in a notch of said joint. 5. A foldable tent according to claim 4 when dependent on claim 2, wherein the handle has a projection which is engagable with said link to prevent return movement of the handle when said joint is in said partially open position. 6. A foldable tent according to any preceding claim, wherein the supporting legs comprise three sections of unequal length. 7. A foldable tent according to claim 6, wherein the legs comprise upper, middle or lower sections and the lower section is longer than the middle section so that when the tent is collapsed the lower section extends beyond the joints. 8. A foldable tent according to any preceding claim, wherein the legs are each connected to a hub at a roof of the enclosure. 9. A foldable tent according to any preceding claim, wherein an elongate flexible element is connected between adjacent legs to maintain tension. 10. A foldable tent according to any preceding claim, wherein the frame is external to the flexible enclosure. 11. A foldable tent substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: NEWTON PAUL RICHARD, NEWTON, PAUL, RICHARD
Applicants: GLASDON LTD, NEWTON PAUL RICHARD, GLASDON GROUP LIMITED, NEWTON, PAUL, RICHARD
Application year: 1994
Main classification: E04H15
IPC codes: E04H15